title: Comparison of different supramolecular architectures for oligonucleotide biosensing.
abstract: This work describes a comparative study between two biosensing platforms that are commonly used to immobilize capture probes. These platforms refer to thiolated and biotinylated oligonucleotide strands chemisorbed on Au surfaces (DNA SAM) and bioconjugated on streptavidin (SA) monolayers (SA SAM), respectively. Both interfacial architectures were studied using surface acoustic wave (SAW) devices and surface plasmon spectroscopy (SPR). Our studies indicated that DNA SAM platforms enable higher densities of surface-confined oligonucleotide probes. However, their hybridization efficiency is lower when compared to that obtained in SA SAM platforms, thus impacting on a lower detection limit, 5 nM. Furthermore, binding of SA molecules to the biotinylated targets, in an attempt to enhance the signal in both platforms, revealed striking differences between both architectures. The SA underlayer used in the SA SAM configuration confers nonfouling characteristics to the interfacial assembly, thus precluding the nonspecific binding of SA onto the surface. The antifouling behavior of the SA DNA platform is an important feature to be considered in the amplification of hybridization events through the bioconjugation of biotinylated targets with streptavidin-based tags.
authors.affiliation: Max-Planck-Institut fur Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany. mir@mpip-mainz.mpg.de
authors.forename: Mònica
authors.initials: M
authors.lastname: Mir
authors.forename: Marta
authors.initials: M
authors.lastname: Alvarez
authors.forename: Omar
authors.initials: O
authors.lastname: Azzaroni
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Knoll
mesh_terms: D000162:Acoustics; D000327:Adsorption; D015374:Biosensing Techniques; D019921:Biotinylation; D004247:DNA / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D008956:Models, Chemical; D008968:Molecular Conformation; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry; D020349:Surface Plasmon Resonance; D013499:Surface Properties
chemical_list: D004277:DNA, Single-Stranded; D009841:Oligonucleotides; D013438:Sulfhydryl Compounds; D006046:Gold; D004247:DNA